In the natural gas and hydrocarbon processing industry, it is frequently necessary to scrub or filter gas before admitting it to a piston type compressor, in order to prevent condensation from reaching the dew point under compression and thereby damaging the compressor mechanism. Gas scrubbers for this purpose must be constantly monitored so that when the liquid removed from the gas reaches a high level, the associated compressor is shut down.
The device of the invention is employed in this environment and is utilized to control a pneumatic vent valve in the pneumatic system which controls the operation of a compressor. By substituting a microswitch for the vent valve, the device can be caused to control an electrical control circuit for machinery rather than a pneumatic control circuit.
The objective of the invention is to provide a liquid level responsive pneumatic vent valve particularly for use in the hydrocarbon processing industry which is characterized by ruggedness and durability, simplicity of construction, and reliability of operation. The invention features a simplified. compact and direct-acting drive linkage between a pivoted float and the reciprocating sleeve element of the vent valve. A uniquely sealed shaft arrangement is employed between the float chamber of the mechanism housing and the pneumatic vent chamber at the other end of the housing.
Other features and advantages of the invention will become apparent during the course of the following description.